Quote Originally Posted by yamazaki
Assuming you have some macro / key set aside to make your main character the focus, you can also do a target=focustarget. Just before healing you target the account you want to be healed then hit the macro.

That way you make it more variable rather than static, and if you decide to make a different account the main then you won't have to change anything.
This is what I opted to do.

/cast [target=focustarget,help] Flash Heal; [target=focus] Flash Heal;